Shuttle grip and strap



Allg 5, 1969 J. s. RUSSELL 3,459,239

SHUTTLE GRIP ANI) STRAP Filed Jan. 17, 1968 AT TORNEYS.

United States Patent O U.S. Cl. 139-207 1 Claim ABSTRACT F THE DISCLOSURE A shuttle grip and strap constructed of steel wherein the bottom plate of the strap has opposed ear portions spaced entirely forwardly of a juncture of the inclined wall of the strap with the bottom plate. Each ear portion includes an enlarged bearing protuberance integral with the ear portions and with the Ibottom plate. Such spacing of the ear portions forwardly from the marginal portions of the thin base of the shuttle avoids formation of hair line cracks in the marginal portions. Such cracks are caused by the present ear portions which extend rearwardly of the juncture overlying the marginal portions, ultimately causing failure of the shuttle body in such marginal portions.

This invention relates to textile shuttles and more particularly to an improved steel strap for positioning a steel bobbin grip therein.

I-Ieretofore, the bottom plate of shuttle straps had ears projecting rearwardly of the juncture of the bottom plate with the inclined bobbin guide wall. It was thought that the ears were necessary for supporting the tip portion of the grip when receiving a bobbin during an automatic bobbin change operation. During such a change operation the full bobbin is urged with great force positively between the tips of the grip to dislodge the spent bobbin and to properly position itself between the tips. After repeated bobbin change operations stress lines and fractures appear in the base material of the shuttle. It has been found that such usually occur in the thin marginal portions ofthe cavity surrounding the bobbin chamber, and is the most common reason for shuttle failure.

Accordingly, it is an important object of this invention to eliminate the most significant cause of shuttle body failure.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing forming a part thereof, wherein an example of the invention is shown and wherein:

FIGURE 1 is a perspective view illustrating a shuttle grip and strap constructed in accordance with the present invention,

FIGURE 2 is a top plan view further illustrating a shuttle grip and strap constructed in accordance with the present invention, and

FIGURE 3 is a transverse sectional elevation taken on the line 3 3 in FIGURE 2.

The drawing illustrates a shuttle grip and strap assembly for use in a shuttle cavity defined in part by a thin base with marginal portions extending to a bobbin' receiving chamber and having a steel gripper spring and a steel grip strap. The gripper spring, designated at A, has a shank portion, a flex portion and a tip portion. The grip strap has a bottom plate body portion B, a top plate C and an inclined wall D joining said bottom plate body portion with top plate. A pair of opposed laterally exice tending ear portions E, constructed of steel, are carried integrally by said bottom plate body portion generally underlying the ex portion of the gripper spring A. The ear portions are spaced entirely forwardly of a juncture of the inclined wall D with said bottom plate body portion B. The ear portions E each include an enlarged bearing protuberance constructed of steel integral therewith, spaced forwardly of said juncture carried upon the thin base remote from the marginal portions thereof. Thus, the bearing protuberances support said gripper spring during a bobbin change operation with minimized stresses upon the marginal portions of the thin base of the shuttle.

A conventional shuttle body which may be constructed of wood or plastic is illustrated at 10. The shuttle grip and strap assembly are received with a cavity 11 which is a continuation of the bobbin receiving chamber 12. The gripper spring A has a conventional U-shaped shank portion 13, flex portions 14, and tip portions 15.

The spring A is supported generally on a bottom plate body portion B which is joined integrally on one end with an inclined wall D of substantially the same width. The Wall D bridges the bottom plate body portion B and the top plate C. The bottom plate body portion B and the top plate C have aligned openings 16 and 17, respectively, for receiving a steel shank 18 of a fastening member for securing the grip and strap assembly within the cavity 11. The shank 18 has a head 19 at the top, and a nut 20 received upon a threaded portion 21 adjacent the bottom thereof. The inclined wall D serves as a guide for the bobbin as it is forcibly inserted by the automatic bobbin change mechanism within the tips 15 of the spring grip A. The force occurring during transfer required to eject the spent bobbin and insert the full bobbin is considerable, and is imparted to a thin base portion 22 of the shuttle body.

The thin base portion 22 has a marginal portion 22a which extends from the central portion of the bobbin receiving cavity 12 around the sides thereof for some distance, as is best illustrated in FIGURE 2. The base plate of former strap arrangements normally included projecting ears (not shown), which extended rearwardly overlying the marginal portion 22a of the relatively thin base portion 22. Such rearwardly extending ears were thought desirable in order to transfer the considerable force engendered by the bobbin change operation to the base of the shuttle.

A pair of opposed laterally extending ear portions E have a forwardly and outwardly tapering edge 23 which originates slightly forwardly of the juncture of the inclined wall D and the bottom plate body portion B. Integral with, and forming a part of, the ear portions E are enlarged bearing protuberances 24, also, constructed of steel and having arcuate edge portions 25 curving inwardly toward the medial portion of the bottom plate B, as best illustrated in FIGURES 1 and 2. The ear portions E and the enlarged bearing protuberances 24 support the spring grip A adjacent the dex portion 14 thereof.

Since the forces exerted upon the spring during a bobbin change operation arei transmitted to the base portion of the strap, and thence to the base portion of the shuttle body, the ear portions, and the enlarged bearing protuberances included therein transmit the force to the relatively thin base portion remote from the marginal portion 22a thereof. It is thought that the hair-line cracks and failures of the shuttle base portion stem from the fact that heretofore, forces engendered by the bobbin change operation were transmited adjacent the marginal portion 22a of the base. Application of the force adjacent the marginal portion is much like tearing a piece of paper from the edge, whereas, it is difficult to tear paper from an intermediate por-tion remote from the edge.

It is thus seen, that the major cause of structural failure of the body portion of shuttles has been alleviated. The rigidity of the steel ear portions which projected rearwardly toward the bobbin receiving cavity have, in effect, applied repeated and substantial forces in the edge portions of the relatively thin base of the shuttle adjacent the bobbin receiving cavity. The object of the present invention is accomplished by the structure set forth above, which imparts force from the springs and through the base plate and projecting ear portions inwardly of the marginal portion of the base and in an intermediate portion thereof.

While a preferred embodiment of the invention has been described using specic terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claim.

What is claimed is:

1. In a shuttle grip and strap assembly for use in a shuttle cavity defined in part by a thin base with marginal portions extending to a bobbin receiving chamber having a steel gripper spring and a steel grip strap; said gripper spring having a shank portion, a flex portion and a tip portion; said grip strap having a bottom plate body portion, a top plate and an inclined wall joining said bottom plate body portion with top plate; the improvement including: a pair of opposed laterally extending ear portions constructed of steel carried integrally by said bottom plate body portion generally underlying the flex p0rtion of the gripper spring; said ear portions being spaced entirely forwardly of a juncture of said inclined wall with said bottom plate body portion; said ear portions each being defined by an outwardly extending edge projecting from said bottom plate body portion entirely forwardly of said juncture, and a forwardly and inwardly extending edge projecting from an outer portion of said outwardly extending edge toward said bottom plate body portion, each of said ear portions being carried upon said thin base remote from the marginal portions thereof; whereby said ear portions support said gripper spring during a bobbin change operation with minimized stresses upon the marginal portions of the thin base of the shuttle.

References Cited UNITED STATES PATENTS 1,580,961 4/1-926 Cheney 139-207 1,675,132 6/ 1928 Prescott 139-207 2,640,507 6/1953 IRickenback 139-207 2,788,024 4/1957 Bousquet 139-207 3,166,101 1/1965 Forster 139-207 JAMES KEE CHI, Primary Examiner 

